Blade Profile Thickness Verification Using Skeleton Curve Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The significant variability in actual excess lengths on raw parts compared to theoretical excess lengths leads to errors in measuring leading edge and trailing edge thicknesses, resulting in inconsistent mechanical strength and aerodynamic performance.

Innovation Solution

A method is proposed to verify the conformity of the aerodynamic profile by measuring only the useful parts of the blade, constructing skeleton curves for both actual and theoretical blades, and using a least squares function to superimpose and compare thickness laws, thereby eliminating the need for reference points on the leading and trailing edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If thickness measurements are taken at fixed distances from the leading and trailing edges on raw parts, then the measurement process is simple and quick, but significant variability in actual excess lengths causes errors in thickness measurements and inconsistent mechanical strength

Engineering Contradiction:
Improvemeasurement speedVSAvoidthickness measurement accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the reference parameter from fixed physical distances from blade ends to curvilinear distances along the skeleton curve. By using the skeleton curve as a reference framework and measuring thickness at points defined by curvilinear distance along this curve, the method adapts to variations in excess length while maintaining consistent functional zone measurements, thereby resolving the contradiction between measurement speed and accuracy

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces the skeleton curve as an intermediary reference framework between the variable raw part geometry and the fixed measurement requirements. This skeleton curve serves as a stable mediator that allows thickness measurements to be taken at consistent functional positions regardless of variations in excess length, eliminating measurement errors while maintaining efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If measurements include the excess length zones at leading and trailing edges, then the complete blade profile is measured, but the measurement time increases and non-functional zones are measured unnecessarily

Engineering Contradiction:
Improveprofile verification completenessVSAvoidgeometric control time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent extracts and excludes the non-functional excess length zones from the measurement process. By defining measurements only within the functional zones bounded by the skeleton curve and using curvilinear distance as the reference, the method removes unnecessary measurements of drop zones while maintaining verification of critical thickness areas, thus reducing measurement time without sacrificing essential profile verification

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different measurement approaches to different zones of the blade. Functional zones are measured with high precision using skeleton curve reference, while non-functional excess length zones are excluded from measurements. This localized differentiation optimizes the measurement process by focusing resources on critical areas only

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4013951B1Method for calculating the thickness of the trailing and leading edges on a blade profile
Publication Date: 2024.06.12 SAFRAN AIRCRAFT ENGINES SAS
  • EP4013951B1 patent drawingFigure 1~3
  • EP4013951B1 patent drawingFigure 4~5
  • EP4013951B1 patent drawingFigure 6~7

AI summary

The invention relates to a method (500) for verifying the conformity of the aerodynamic profile of an actual blade of an aircraft turbine engine with respect to a theoretical blade, which comprises: - constructing (521) a skeleton curve of the theoretical blade and constructing a skeleton curve of the actual blade, - constructing (522) a thickness law of the theoretical blade and constructing a thickness law of the actual blade, the thickness law of a blade corresponding to the curve of the thickness of the blade as a function of the curvilinear length of the skeleton curve from a leading edge of the blade to a trailing edge of the blade, the thickness being the dimension of the blade that extends perpendicular to the skeleton curve at each point of the skeleton curve, - superimposing (523) the thickness law of the actual blade on the thickness law of the theoretical blade, and - extracting (524) the leading and trailing edge thicknesses.